Conventional work tools such as impact rock breakers and rippers comprise a shank having a tip mounted on the nose thereof by a pin or other suitable retaining or retention means extending through openings in the shank and tip. Unless the nose of the shank is held in continuous bearing contact with the tip, the pin, the shank and/or tip may be subjected to damage. Consequently, the retention means should fit tightly between the shank and tip to firmly secure these latter two members together. It is further desirable that the retention means be adapted to expeditiously mount the tip on the shank and be capable of expeditiously demounting the same for servicing purposes. A problem with prior retention means is to design them for easy entry into and removal from the shank and tip openings, yet enable them to bear firmly in contact with the shank and tip once they are lodged in such openings for secure mounting purposes.